Is there a more efficient way to charge an ATV agm battery from my solar setup then a 3 amp charger connected to an inverter?

I have a small solar setup for my shed to avoid running a power line out to it. I have an ATV that needs a trickle charger connected to maintain the Agm battery.
This is my setup...HQST 100 Watt 12V Monocrystalline Solar Panel, RICH SOLAR 20 Amp 12V/24V DC Input MPPT Solar Charge Controller, RICH SOLAR BT-1 Bluetooth Module, Interstate 27d marine battery, Bestek 1200w modified sine inverter.
When connecting a small 3amp charger to the inverter, it seems to pull the charge of the main battery down quickly. Is there a way to charge the all ATV Agm battery directly from the charge controller or my Deep cycle battery? Thanks!

Hook it up directly, set a timer.

I think a 3 amp charger is a bit much for a trickle charger. I use a .75 amp plug in trickle charger on dual battery diesel.

Either way, I’ve found these trickle chargers use way more power than the 36 watts you would think you get from a 3 amps X 12 volts = 36 watts when plugged into a VAC circuit. Electricity is charged pennies by the KWh, so there’s no incentive to make them efficient.

So, I think any number of auto parts solar trickle charger would do fine, or you could hook low watt panel up to a SCC. I don’t see a need to trickle charge the battery with solar 24 hours by including a battery and an inverter.

Prior to moving my diesel truck indoors, those two batteries in it were kept charged by a solarizer trickle charger. This was a small panel, probably 5 watts. I left the diesel untouched for up to six months and it started like a champ.

The only exception I see to having to use an extra battery to power an inverter would be if you’re prone to many days of bad weather or you have extremely short winter days.

You could also use a Victron 12 VDC to 12 VDC converter that has a battery charge mode or a VIctron 12 VDC to 12 VDC charger. The particular Victron converter I looked at had a negligible idle draw, unlike my inverter which was 1 amp per hour. Those efficient converters get pricey though.

All said and done, a trenching tool to add a 15 amp circuit from the house to the shed may be the cheapest and most reliable solution.

Charge the AGM and disconnect. Repeat at each use or at six months. Float on the AGM is unneeded and inefficient.

For trickle charging flooded lead acid (in my case, the group 65 starter battery in my van, I directly connect a 12V panel which is too small to over charge the battery. Maybe 10W (I have 25W on there right now, but, it's sitting on the dash, so, with the loss through the windshield, and the limited time when the solar angle is good, it seems to work out).

time2roll said:

Charge the AGM and disconnect. Repeat at each use or at six months. Float on the AGM is unneeded and inefficient.

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Actually it's just the opposite. But most won't notice it - at first.

If you don't float, 1% of it hard sulfates and is for the most part not recoverable. On a 100ah battery after month, will you notice that it is now really a 99ah battery? No. After 6 months, will you notice that it is now a 94ah capacity? Will you actually take the time to test this? No.

This is how agm under-charge "walk-down" creeps up on you unnoticed. Most people are ok with this. Dealers especially. It's also the reason that most solar installations that use AGM that never achieve much float time are quick to die and need replacement - unless special steps are taken.